After
buying an iRobot Roomba (a vacuum cleaner so cool that you
have to go and clean your friends' houses as well), I saw this "RoboSweep"
advertised. only $39.99!

"ROBOSWEEP
- The intelligent sweeper that sweeps while you rest"

"Robo
Sweep intelligently sweeps back and forth to clean the whole room in
minutes, while you rest!"

So
I figured I would buy one and see what it was. it just arrived today in
a box glossy box:

I
pulled it out of the box and here it is:

Ok,
this thing really feels like plastic and weighs nothing.

It
is covered with little Velcro spots to hold the 'wipe' and has almost
no ground clearance.

There
are two little wheels at the back which just free-spin (not motor driven)
and some kind of steering turret near the front.

No
visible sensors from the outside.

I
installed the 4 x AA rechargeable batteries and plugged it into charge
(recommended 6 hours).

After
6 hours I installed a wipe and let it go on my kitchen floor.

It
crawled (and I mean crawled) off as I just stood there waiting.

After
an excruciating minute it finally reached the wall and it slowly turned
around and started off in a new direction.

The
stopwatch test - it screams along at the blistering rate of a foot every 3 seconds... it would take it a minute to
just reach the other side of of a 20 foot living room.

After
another minute I was so bored that I picked it up to see what it had done.
the wipe was completely clean but it was starting to push dirt in front
of it. The ground clearance is so low that the dirt can't go under it
to reach the wipe!

Ok,
I had resisted long enough. out came the screwdriver J

I
wonder what kind of processor this 'intelligent' robot has in it?

Ok,
I see:

One motor.

One battery tray.

One switch.

One power socket.

One LED.

A few wires.

Things
I don't see:

A circuit board.

A processor.

Any sensors.

Any intelligence.

Any ability to do anything but spin the one motor
J

So
how do this thing pretend to work?

There
is a small plastic gearbox that works a bit like the differential in a
car.

If
the robot is on the ground then the gearbox turns the little wheels and
the robot moves forward.

When
the robot gets stuck the force of the motor has to go somewhere and the
gearbox 'slips' and rotates the turret instead (until the wheels start
moving again).